This invention relates to a process for molding a thermoplastic resin blank in a compression die to form a thermoplastic resin molding, and also to the molding molded according to said process.
Processes for molding oriented molded products of thermoplastic resins according to compression molding have been described in, for example, U.S. Pat. No. 3,632,841 and others. More specifically, it is shown that the inner surface of a compression die is coated with a lubricant, and a thick thermoplastic resin blank is compressed within the compression die at a temperature higher than the glass transition point but lower than the melting point to be biaxially oriented. According to this compression molding method, the compression force required is different depending on the thickness of the resin blank, and the higher compression force is necessary as the blank is thinner. Therefore, according to this compression molding method, molding of a thin biaxially oriented sheet has heretofore been inefficient and uneconomical.